The available evidence on the ecological factors favoring the existence and origin of natural parthenogenesis is evaluated. Analysis of the geographical distributions of the well-known cases of animal parthenogenesis in nature reveals (i) that most of these species exist in natural disclimax communities and (ii) that within these communities they exist in… (More)
A total of 175 skin grafts were transplanted among 20 individuals belonging to two separate populations of the parthenogenetic lizard Cnemidophorus uniparens. Of these, 98.8 percent were permanently accepted, which indicates that all individuals of each population may be genetically identical. These results further suggest that large populations or the… (More)
The strict avalanche criterion (SAC) is one of the desirable properties in the functions to be used for cryptographic purposes. This paper presents an application of this to evaluate the present diffusion algorithms pseudo-random number generation (PRNGs). So, to measure the statistical independence of the outputs towards the input parameters.
The Cryptographics Algorithms AES and Twofish guarantee a high diffusion with the use of fixed MDS matrices of size 4 × 4. In this article variations to the Cryptographics Algorithms AES and Twofish are made. They allow that the process of cipher-decipher come true with MDS matrices selected randomly from an algorithm that obtaining an MDS matrix of set of… (More)
Postreproductive Cnemidophorus uniparens maintained under free-running conditions of constant darkness for 7 months became reproductive at the same time as controls exposed to a long photoperiod. This lizard exhibits a pause in reproductive activity (refractory period) commencing in late summer in nature and terminating in mid-December in captivity. Both… (More)
19 animals had eggs excised from the oviducts soon after ovulation. Number of clutches was nearly tripled in excised animals as compared to controls. An influence of eggs in the oviduct on number of clutches is suggested and may indicate a neuronal link between oviduct and hypothalamus.